1,314 will be women, the most in any Winter Olympics to date.
The official mascots for the Tokyo 2020 Olympics and Paralympics were unveiled at a ceremony in downtown Tokyo on Sunday.
"I believe the Tokyo 2020 Games will generate more enthusiasm than ever".
Japan is now experiencing a heatwave that has left over a dozen people dead and hospitalised thousands, leading to fears of similar problems when the Olympics rolls into town in two years' time. But anyone who has spent a summer in Tokyo knows that's not necessarily the case.
Experts have warned the risk of heatstroke in Tokyo has escalated in recent years, while noting the Olympics are expected to take place in conditions when sports activities should normally be halted.
The FIS Congress 2018 made a decision to propose further competitions for inclusion on the Games program: nordic combined Ladies' individual event, snowboard alpine mixed team parallel event, snowboard parallel slalom, and telemark parallel sprint, but they will not be on the program for the Beijing 2022 Olympic Winter Games.
Coates, the chairman of the IOC's Coordination Committee for the 2020 Games, also highlighted transport as a major challenge still remaining for organizers.
In a country that has a fondness for mascots, Tokyo 2020 organisers sought to create lovable characters for the Games with both selections said to have superpowers and an ability to teleport between the digital world and reality.
The Japanese government and the Tokyo metropolitan government are planning to lay pavements that emit less surface heat and plant taller roadside trees, but many worry it will not be enough.
Meanwhile Coates has urged Tokyo organizers to rely more heavily on foreign expertise in staging events where Japan does not have a strong background.
Authorities have been criticised by various sports federations over issues such as competition planning, water pollution and communication channels.
"Obviously in sports in which Japan is not traditionally strong, and doesn't have a lot of experience in, then more liaison work with global federations is necessary", Kyodo News quoted Coates as saying.